Diet Soda Doesn’t Help You Lose Weight

2013-12-10

Diet soda is falling out of favor. According to new research from Wells Fargo, low-calorie and zero-calorie soda sales slipped about 7% over the past year. Regular soda has fallen just over 2%.

The reason remains a mystery, but perhaps folks are realizing that the benefits of drinking diet soda are just not there. At least, if you’re trying to shed pounds.

Several studies in the past couple of years have torn holes in the theory that zero-calorie sodas mean zero weight gain. Indeed, research presented at the American Diabetes Association’s (ADA) Scientific Sessions in 2011 showed the opposite is true—diet sodas can actually contribute to weight gain.

How? There are a few theories. First, scientists speculate that artificial sweeteners fool more than just your palate; they also fool your brain. When you taste something sweet, your body naturally expects a calorie-load that diet beverages don’t deliver. As a reaction, the metabolic system may start converting the sugar that’s already circulating in the blood into fat, on the assumption that more has just come in that can be used as energy. In the alternative, the body may go in the other direction, burning though the circulating sugar so that the incoming soda doesn’t leave you with too much. But since the soda has no sugar at all, you wind up with a net loss—which may lead to a craving for candy or some other high-sugar snack.

It’s also possible that the lack of calories causes diet-soda drinkers to overeat later for psychological reasons. They either feel unsatisfied and eat more to make up for it, or they think they saved on calories earlier by opting for diet soda—a handy justification for eating more.

The plunging sales numbers may suggest that consumers are catching wise to all of this. The solution: it’s better to kick the soda habit and stick to water.

(No) Condom Culture: Why Teens Aren’t Practicing Safe Sex

2013-12-04

By Katy Steinmetz

There were certain things that the 1990s just did better — including getting the word out about the dangers of unprotected sex.

According to the Centers for Disease Control and Prevention (CDC), the percentage of American students using condoms hit its peak at around 60% a decade ago, and has stalled since then, even declining among some demographics. A recent study released by the Sex Information and Education Council of Canada found that nearly 50% of sexually active college students aren’t using condoms. Other reports have found that while teenagers are likely to use a condom the first time they have sex, their behavior becomes inconsistent after that.

Health officials from Oregon to Georgia are ringing alarm bells about rising rates of sexually transmitted diseases, worried that kids aren’t getting the message. Sex education is more robust than it was for previous generations, but a 2012 Guttmacher Institute report revealed that while nearly 90% of high schools are teaching students about abstinence and STDs, fewer than 60% are providing lessons about contraception methods.

The CDC estimates that half of new STD infections occur among young people. Americans ages 15 to 24 contract chlamydia and gonorrhea at four times the rate of the general population, and those in their early 20s have the highest reported cases of syphilis and HIV. Young men and women are more likely than older people to report having no sex in the past year, yet those who are having sex are more likely to have multiple partners, which increases the risk of STDs.

“We need to do better as a nation,” says Laura Kann, an expert in youth risk behaviors at the CDC. “Far too many kids in this country continue to be infected with HIV and continue to be at risk.”

When condom-usage rates were on the upswing in the ’90s, America was in the midst of an AIDS epidemic that was claiming young lives daily. The fear of the disease gave heft to safe-sex campaigns. Today, public-health officials are partly a victim of their own success; contemporary teenagers grew up after the terror had subsided, thanks to antiviral drugs and those messages that helped bring infection rates down. “The young people today know HIV as a manageable, chronic disease,” Kann says. “It’s not something that can kill you in their eyes. So that leads, most likely, to an attitude that it’s not something that they have to protect themselves from.”

In Oregon’s Lane County, senior health official Patrick Luedtke is in the midst of confronting an ongoing gonorrhea outbreak, with rates jumping as much as 40% in recent years. Like Kann, he believes complacency is a large part of the problem. “People don’t have the fear of death from sex like they had 15 years ago,” he says. “For the teenagers, that fear is gone, and people are not practicing safe sex as much as they used to.”

Other research collected by the CDC shows that some schools aren’t hammering away at the safe-sex lessons like they once did. In Alabama, Alaska and Florida, for instance, fewer public schools are teaching teenagers how to obtain condoms and why it’s important to use condoms. “Schools have competing health issues that they’re asked to deal with, things like tobacco use, bullying, the obesity epidemic. It’s been hard to keep attention focused on HIV and STD prevention,” Kann says. “This complacency issue [is not] unique to just youth themselves.” Last week, the American Academy of Pediatrics issued a policy statement supporting better access to condoms for teenagers, saying schools are still hesitant to provide them because of an enduring fear that access to condoms will make kids have more sex.

Public institutions beyond schools have had setbacks too. Budget cuts in Oregon meant that Luedtke’s county closed its STD clinic. “People don’t stop having sex because of the bad economy,” he says. “Where are the resources?”

Even in places where there’s money and free condoms to go around, health departments haven’t necessarily seen safe sex go viral. New York City health officials are reporting that only 1 in 3 adult residents uses protection, despite years of PSAs and prophylactic handouts under Mayor Michael Bloomberg. While condom use among young people in New York City is slightly up since 2009, that puts it on par with the stagnant nationwide average.

Kann says there are broader societal factors at work too, ones that disproportionately affect African-American youth. Compared with the population as a whole, their parents are less educated and have lower incomes, both factors that have been linked to sexually risky behaviors, including having unprotected sex. Adolescents who postpone sex have parents who are more educated. Lower incomes, meanwhile, are associated with factors like parents working multiple jobs, which can mean kids are left home alone without a watchful eye to factor into their decisionmaking.

Some research has suggested that sexually active Americans simply assume their partner is free of STDs, and an infected partner may be unaware, given that diseases like “silent” chlamydia often don’t have obvious symptoms. And there is a perception — if not a diehard belief — that using condoms makes sex less pleasurable. That’s why Bill Gates challenged designers earlier this year to create a better-feeling condom that sexually active people might be more likely to use.

While it’s hardly a sexy, revolutionary proposition like remaking the condom, Kann says the key to driving condom use higher is more education. Canada’s survey, for instance, was revealing about how relatively unimportant the students considered STDs. Those who used condoms were much more likely to cite pregnancy than STDs as their main concern; 54% said their single motivation for using protection was birth control, while just 6% cited STDs as their sole reason.

“It’s really critical for kids to know about their risk,” Kann says. “They need to know how to get tested. They need to know how to prevent infection. And we can’t do that alone here at CDC. We’re going to need action not only by this agency but also by parents, by schools and communities.”

You Can’t Be Fit and Fat

2013-12-03

It’s okay to be heavy, as long as you don’t have diabetes or hypertension–right? Not so fast, says the latest research.

There are always exceptions to the rule, and that’s true of health issues too. While the bulk of studies warn about the dangers — to the heart, liver, kidneys and other body systems — of gaining weight, a small number of trials suggested that some overweight or obese individuals may be as healthy as their normal weight counterparts, since they had normal blood pressure, no diabetes and relatively stable cholesterol levels. In fact, one study found that overweight individuals (but not obese people) tended to live longer than those of normal weight.

But in a comprehensive review of studies dating back to the 1950s, scientists contradict that idea, with evidence that it’s not possible to be both overweight and healthy.

The researchers, from Lunenfeld-Tanenbaum Research Institute at Mount Sinai Hospital in Toronto, Canada, found that people who tipped the scales at above their recommended body mass index (BMI) but did not have abnormal cholesterol or blood pressure, for example, still had a higher risk of dying from heart disease over an average of about 10 years compared to metabolically healthy individuals within normal weight ranges. In their analysis, published in Annals of Internal Medicine, the researchers separated individuals in the previous studies into six groups: normal weight and healthy, normal weight and unhealthy, overweight and healthy, overweight and unhealthy, obese and healthy, and obese and unhealthy. Their results showed that regardless of the person’s BMI, an unhealthy metabolic state — such as having hypertension, diabetes or high cholesterol levels — was consistently linked to an increased risk of dying during the study period or having a heart event. And contrary to previous studies that suggested that heavier people with normal metabolic readings could have “benign obesity” or “metabolically healthy obesity,” the team also reported that metabolically healthy obese participants had a higher risk of dying earlier or having heart-related problems than those who were normal weight and also metabolically healthy.

Why did previous studies suggest that people could be fit and fat? According to the current study’s lead author, Dr. Caroline Kramer, the discrepancy likely has to do with how the various studies were set up. For instance, some large studies only compared weight and the risk of adverse events instead of looking closely at people’s metabolic health. So some of the apparently healthy but overweight or obese individuals might have had signs of diabetes or hypertension or high cholesterol that simply weren’t recorded in the study. Other trials compared healthy obese people to unhealthy obese people, instead of comparing them to people of normal or healthy weights, and other studies relied on small groups of participants who were only studied over short time periods.

“This concept of healthy obesity came in the last 10 years, and it compares people who are obese but metabolically healthy to only metabolically unhealthy overweight people,” says Dr. Kramer. ”Some studies report that if you are obese but metabolically healthy, you are protected in a way. We don’t think that that is true. And I don’t think it will come as much of a surprise.”

But since obesity has different effects on the body for different people, researchers are still investigating how weight gain and its health effects may vary among people whose obesity is due primarily to things such as genetics and environmental exposures as opposed to unhealthy diets and lack of physical activity. Even the studies in the current meta-analysis, for example, did not all include follow-up with the participants, so the final mortality and heart disease rates may be slightly higher or lower than they should be. But for now, the advice about maintaining a healthy weight in order to avoid premature death and disease seems sound — there may not be a way to heavy and healthy at the same time.